Don't know what goes into the sauce, but don't for one minute imagine that there is a guy sitting out the back chopping and mixing ingredients.
They buy it in large catering jars from the Cash and Carry.
The Chilli Sauce used in the North East of England is deffo made on hte premises. I know in other areas of the UK I have had chilli sauce that tasted out of a jar, kind of tomato kethcup style, but here in the North East it is more like a very fine fresh salsa type sauce. I would love to know whats in it so I can replicate it at home